Boeing vs Airbus: Yokes vs Side Sticks in Aircraft Controls

Boeing aircraft traditionally use yokes, while Airbus aircraft use side sticks. The discussion revolves around the possibility of Airbus transitioning to side sticks and the implications for existing aircraft.

The Airbus A300, introduced in 1972, initially featured yokes for flight controls. Subsequent versions added fly by wire technology but retained the yoke design until recent production. The Airbus A320 family was the first to introduce side sticks in 1987.

Fly by wire technology was first used in military jets in the 1960s, with the F-16 being the first operational aircraft. Airbus introduced fly by wire to airliners with the A320 family, while smaller aircraft like the Cirrus SR20 also utilize side sticks.

Fly by wire technology enhances consistency, safety, and ease of operation in airliners. It allows for uniform handling across aircraft models, aids in pilot training, and prevents serious aircraft upsets by operating within safe flight parameters.

Boeing has incorporated fly by wire technology in aircraft like the 777 and 787 over the last three decades. The 777 and 787 are full fly by wire designs, contributing to enhanced safety and operational efficiency.

Boeing's decision to use yokes instead of side sticks in the development of the 777 in the late 1980s and early '90s is highlighted. This choice contrasts with Airbus's use of side sticks and reflects Boeing's unique approach to flight controls.

Boeing considered using a side stick in the 777, similar to the 7J7 conceptual design, but ultimately decided to stick with traditional yokes. The decision was influenced by factors like ergonomics, weight, and maintaining layout consistency with previous aircraft models like the 757.

Yokes in Boeing 777 and 787 aircraft, despite being bulkier than side sticks, offer benefits like synchronized movement for both pilots and a more substantial structure. This design choice also contributes to a familiar layout for pilots and facilitates easier servicing and replacement.

Collins Aerospace highlights an 80% weight reduction with side sticks compared to yokes in a similar setup. The compact design of side sticks, primarily consisting of wiring and mounted on top, requires less space and weight, making them advantageous in terms of aircraft weight management.

The introduction of side sticks in aircraft represents a significant advancement in control mechanisms. These sticks not only transmit pilot inputs but also include servo mechanisms to exert force against pilot movements. The ability to program side sticks to move correspondingly enhances control precision and safety measures in critical situations.

Criticism of side sticks includes issues like dual input conflicts between left and right sticks during critical moments, leading to audio warnings. Additionally, concerns arise regarding the lack of feedback from the trim system, especially in scenarios where the aircraft operates in a degraded mode like direct law.

Airbus has designed warning systems that include a warning system with visual warnings and messages to alert pilots if the aircraft is out of trim. These systems have been continuously improved over the years to enhance safety measures.

Active side sticks have been developed for aircraft, resembling force feedback joysticks. The technology has evolved over time, with the first aircraft designs incorporating them as standard being a Business Jet, a military aircraft like the Embraer KC-390, and an airliner like the Russian Irkut MS-21 or MC-21.

The Russian Irkut MS-21 was set to become the world's first airliner with active side sticks, but due to current sanctions, the timeline is uncertain. There is a possibility of other airliners entering service with active side sticks before the MS-21, with Airbus and Boeing likely to introduce them in the next few years, possibly as retrofits for existing aircraft.

Technology upgrades in aviation have been significant, with advancements in electronic equipment allowing for the replacement of older systems with newer, more efficient ones. The introduction of active side sticks as line replaceable units (LRUs) offers easier removal and replacement, potentially enhancing aircraft systems.

Active side sticks offer advantages over existing designs, such as improved communication between pilots to determine control of the aircraft and quick identification of trim issues in degraded control law situations. Their adaptability to fit into various aircraft cockpits like Gulfstream and A320 provides a promising future for aviation safety.

Active sticks offer several benefits, including improved feedback to pilots when the aircraft is on autopilot, corresponding movements to control surface deflection, and warnings to pilots about impending actions. These advantages are not present in Boeing cockpits with yokes. Additionally, active side sticks provide benefits such as lower system weight, easier maintenance and replacement, better ergonomics, and the inclusion of a tray table.

In April 2022, pilots flying a Boeing 777 from New York to Paris engaged in a conflict during the approach due to desynchronized yokes. The French investigating authority, BEA, highlighted the issue of split or desynchronized yokes when pilots input conflicting controls, emphasizing the potential risks associated with such incidents.

Instances of jammed yokes and side sticks have raised concerns about the need for feedback mechanisms to prevent conflicts between pilot inputs. Retrofitting aircraft with active side sticks could address these issues, potentially enhancing safety and reducing the likelihood of incidents related to control conflicts.

Various manufacturers produce active side sticks for different aircraft models. BAE Systems supplies active sticks for Airbus aircraft, Ratier Figeac manufactures them for the Irkut MS-21, and Collins Aerospace, a part of RTX (formerly Raytheon), provides them for Embraer's KC-390. The similarity in design between these active sticks suggests a potential for cross-platform development and adoption in the aviation industry.

The introduction of active sticks in aviation technology presents a promising solution to address the limitations of previous control systems. Airbus pilots' perspectives on the benefits and challenges of transitioning to active sticks could provide valuable insights for future implementations. The potential for flight control updates and the adaptation of active stick technology across different aircraft models may shape the future of aviation safety and efficiency.